1. Field of the Invention
The present invention relates to an elevator system without a machine room, and in particular to an improved elevator system without a machine room which is capable of enhancing an adaptability of a design and installation and a durability with respect to a load and vibration and implementing an easier maintenance by installing a thin type winding machine in the interior of a hoistway and removing a machine room which is installed on the top of the hoistway in the conventional art.
2. Description of the Background Art
An elevator system is used for rapidly moving people or freight between floors of a building. As society is industrialized, the elevator system is necessarily installed in buildings. In addition, the elevator system is used for various purposes in the industry.
As the use of the elevator system is increased, a user needs a better performance of an elevator system. Currently, the elevator system is intensively studied on a speed, capacity boarding-on feel, durability, etc. In particular, in a view of loading people therein, a safety problem attracts a big attention from many people. In many countries, there is a very strict rule for the safety of the elevator system for thereby implementing a stable elevator system.
When installing an elevator system, a building owner has various installation methods. Generally, the building owner wishes to install an elevator system based on a good price compatibility, good durability, easier maintenance, and short construction period. Many elevator system fabrication companies have studied the elevator system based on the above-described trends.
In a conventional typical elevator system, an elevator car is suspended in a hoistway by a wire rope, and a left and right movement of the elevator car is prevented by a guide rail. A machine room is installed at the top of a building. A winding sheave connected with a motor, control panel, etc. are installed the machine room. The rope connects the winding sheave and a counterweight along a groove of a pulley which is additionally installed. The counterweight compensates the counterweight of the elevator car so that a motor unit effectively drives corresponding elements of the elevator system. The counterweight is guided by a counterweight guide rail for thereby preventing a left and right movement of the same.
In addition, in a case of a high building, in order to overcome a unbalance between the elevator car and the counterweight, a compensation rope is connected between the elevator car and a lower portion of the counterweight for thereby compensating an eccentric load of the counterweight of the wire rope.
In the above-described elevator system, a 1:1 roping method is directed to connecting the elevator car and the counterweight using a rope for thereby transferring a driving operation of the winding sheave based on a 1:1 method.
In a 2:1 roping method, a pulley is not installed at an elevator car and counterweight, respectively, and a rope is not directly connected with the elevator car and the counterweight. In this roping method, the rope is connected with an upper portion of a building through the pulleys, so that the elevator car and counterweight are lifted and lowered by the half of the length of the rope when the winding sheave is rotated. Therefore, the motor unit is driven at a 2-times speed compared to that of the 1:1 roping method, so that a rotation torque becomes half.
In the above-described elevator system, the control panel controls an electric power supplied to the motor unit and a rotation speed and rotation torque. When the motor unit is rotated, the winding sheave fixed at a shaft of the motor unit is rotated, and the rope wound onto a groove of the winding sheave is moved in a certain direction by a friction, so that the elevator car is lifted and lowered based on the moving direction of the rope.
In the elevator system, Since the elevator car is pulled using a rope at the top of the elevator system, the winding apparatus must be installed at the top of the hoistway. In addition, in order to protect the machine room from other surrounding environments, the machine room is separately installed, and the winding apparatus and control panel are installed in the interior of the machine room.
As an example of the above-described conventional elevator system, in the Japan utility Model Pyung 4-50297(Title: Small elevator), the driving apparatus of the elevator car is installed at a mount fixed at the guide rail. Since the driving apparatus is positioned at a height same as the height of a ceiling of the elevator car and is housed in the interior of the hoistway and is protruded at the upper portion of the hoistway or from the hoistway, so that the machine room is not needed for installing the driving apparatus therein. Therefore, in this case, the above-described small elevator is proper to a small size house. In addition, a compact elevator may be available.
In the above-described conventional small elevator, a guide rail is installed from a lower portion to an upper portion of the hoistway for guiding the cage, and a counterweight guide rail is installed from a lower portion to a lower portion of the upper portion of the hoist way, so that it is possible to obtain a certain space for installing the driving apparatus between the mount fixed at the upper portion of the counterweight guide rail and the ceiling surface of the hoistway. Since a decelerating and winding apparatus which are a typical driving apparatus for driving the elevator car is installed in the installation space, it is not needed to additionally install a machine room at the upper or side portion of the hoistway, so that the small elevator is proper to a small house.
In the above-described elevator system, since a small capacity deceleration motor and sheave are installed in an installation space formed between the ceiling surface of the hoistway and the upper mount of the counterweight guide rail, the small elevator is proper to a small house for servicing passenger smaller than 6. The above-described small elevator is not applicable for an intermediate size elevator system and a large size elevator system which serve a large number of the passenger. In addition, since a space formed at an upper portion of the hoistway is small, there is a limit for installing the driving apparatus therein, and the selection of the winding apparatus is limited. In the typical elevator system in which a sheave is engaged at the shaft of the decelerating motor, and a rope is wound onto the sheave for thereby driving the elevator car, in the case that the number of passenger is increased, the sizes of the decelerating motor and sheave are increased, so that it is impossible to separately install the machine room at an upper portion of the hoistway or an outer portion of the same in the known manner.
As another example of the conventional elevator system, in the U.S. Pat. No. 5,036,954 (Title: Elevator), in the elevator which includes an elevator car, a guide rail for moving a counterweight therealong, a rope for suspending the car and counterweight, a sheave for moving the car and counterweight using the rope, and an elevator hoistway, the length of the rail used for moving the counterweight is shorter than that of the rail for moving the elevator car, and the guide rail for the counterweight is positioned at an upper portion of the hoistway.
In the above-described elevator system, the distance of the movement of the counterweight is shorter than the distance of the movement of the elevator car, and the ratio between the cross-sectional area of the elevator car and the cross-sectional area of the hoistway is increased. Therefore, it is possible to use the space formed below the counterweight. Since the guide rail for guiding the movement of the counterweight is installed at an intermediate upper portion of the hoistway, a certain support member is needed for stably supporting the lower portion of the guide rail in the intermediate space portion of the hoistway. Therefore, it is difficult to install in the interior of the narrow hoistway. In addition, in a structure that the lower portion of the counterweight guide rail is not supported by a support member, namely, the lower portion of the same is suspended by the upper portion, and the side portions of the same is supported, the stability and durability are decreased.
In the above-described elevator system, the driving apparatus is installed in an upper space portion of the hoistway spaced-apart from the upper portion of the counterweight guide rail. In this case, since the driving apparatus of the winding apparatus formed of a deceleration motor and a sheave is installed in the interior of the hoistway, the selectability and adaptability of the design are decreased for adapting to a large capacity elevator system.
In the U.S. Pat. No. 5,429,211 (Title: Traction sheave elevator), there are provided an elevator car moving along the guide rail, a counterweight moving along a counterweight guide rail, a hoisting rope set for suspending the elevator car and the counterweight, and a driving machine unit formed of a traction sheave driven by the driving machine unit and connected with the hoist rope. The driving machine unit of the elevator is installed on the top of the hoistway between the moving way of the elevator car or the extended portion thereof and the hoistway needed for the movement of the elevator car.
Since the above-described traction sheave elevator is installed in an upper space portion formed so that the winding apparatus of the driving machine unit is position higher than the elevator car when the elevator car is positioned at the highest portion, the installation space of the floor is increased. In addition, since the winding apparatus is fixedly installed by a support apparatus at the upper side space portion of the hoistway spaced-apart from the guide rail, the installation structure is complicated.
In the U.S. Pat. No. 5,823,298 (Title: Traction sheave elevator), the sheave elevator having a traction sheave and a driving machine is installed in a hoistway in which a guide rail is installed for guiding the movement of the elevator car and counterweight. The hoising rope is upwardly moved by the traction sheave. The above-described traction sheave elevator includes two conversion pulleys installed at an upper portion of the guide rail, and one conversion pulley is moved from the traction sheave to the elevator car, and the other conversion pulley moves a part of the hoisting rope from the traction sheave to the counterweight.
In the above-described traction sheave elevator, a winding apparatus is installed at an intermediate portion of the hoistway distanced from the elevator car guide rial and the counterweight guide rail. For example two conversion pulleys are engaged at an upper portion of the counterweight guide rail and are supported like a cantilever, and a traction rope is wound onto a winding apparatus of the intermediate portion and an upper conversion pulley and then is connected with the elevator car and the counterweight, and both ends of the traction rope is connected with an upper wall of the hoistway and an upper portion of the counterweight guide rail. A traction load of the rope applied to the pulley by the driving force of the winding apparatus is applied in a certain direction, so that the stability and durability are decreased. Since the winding apparatus is distanced from the guide rail and is fixed at an intermediate wall portion of the hoistway, the selectability and applicability of the design of the cross section of the hoistway are decreased.
In the U.S. Pat. No. 5,878,847 (Title: Arrangement for fixing an elevator rope), at least one end point of the elevator rope is connected with the elevator car guide rail and the counterweight guide rail, and the elevator car is suspended by the rope, so that all vertical direction loads are applied to the bottom of the hoistway by the elevator car guide rail and counterweight guide rail.
In the above-described rope arrangement for fixing the elevator rope, it is possible to easily install the elevator, and since all vertical direction loads are transferred to the bottom of the hoist way, the structure of the hoistway wall becomes light.
However, in the above-described rope arrangement, since there are provided a pulley at an upper portion of the guide rail, a winding apparatus, and other elements, the construction of the upper portion of the hoistway is complicated, and the length of the hoistway is increased. In addition, since a heavy apparatus such as the winding apparatus, other elements, etc. is installed at an upper portion of each guide rail like a cantilever, the vibration of the guide rail is increased, so that the durability is decreased, and vibration noise is increased.
In the U.S. Pat. No. 5,899,301 (Title: Elevator machinery mounted on a guide rail and its installation), an elevator machine having a disk type motor (hereinafter called as a disk type winding apparatus) is installed at the elevator car guide rail or the counterweight guide rail, and the guide rail in which the disk type winding apparatus is installed is an element capable of increasing the machinery driving force of the disk type winding apparatus, and the vertical direction load applied to the traction sheave by the elevator rope passes through the guide rail through a rolling center of a bearing. The disk type winding apparatus includes a damping system for damping a movement and vibration.
In the above-described various elevator systems, a conventional typical elevator, namely, an elevator having a machine room at the top of the hoistway, requires more construction materials and workers for fabricating the machine room, and the size of the entire structure is increased.
In addition, the total counterweights of the elevator car, counterweight, and wire rope are supported by the winding apparatus, and the winding apparatus is supported on the bottom of the machine room. Therefore, the total counterweights are applied to the entire structure of the building. A building is designed based on the above-described total counterweights and a support structure and a load bearing wall, so that more material, time, and workers are requires, and there is a limit for determining an installation site of the elevator system.
A machine room is protruded on the top of the building, an external appearance of the building is bad, and there is a limit for designing the building.
In the case that there is a building height limit in a certain area, the height of the building is limited by the height of the machine room.
The elevator using a disk type winding apparatus is lighter than the typical winding apparatus which is formed of a deceleration motor and a sheave engaged to the shaft of the motor, and a smaller installation space is needed, and the maintenance cost is decreased.
The above-described disk type winding apparatus is a thin type capable of adapting the principle and type of a known motor and has a trademarked name of ECODISC (KONE Corporation, Finland). In the elevator system without a machine room, a machine room is installed on the top of the building, so that more fabrication cost is needed, and the external appearance of the building is very important. In the above-described U.S. Patents, a new elevator structure without a machine room and a new wire rope arrangement are disclosed.
In the above-described conventional elevator system without a machine room, since a disk type winding apparatus is installed at an upper portion of the elevator car guide rail or the counterweight guide rail, the vibration and swaying state are applied to the upper portion of the guide rails when the elevator car and counterweight are moved, so that noise is increased, and the durability is decreased.